Cedrenone is a known sesquiterpene compound represented by the following formula (I): ##STR1## and can be obtained by chromic acid oxidation of .alpha.-cedrene represented by the following formula (III): ##STR2## or by autoxidation of .alpha.-cedrene using cobalt resinate as disclosed, for example, in Kato, Perfume, No. 123, p. 31 (1978).
Each of these prior art cedrenone production processes, however, has disadvantages in that it requires not only a prolonged period of reaction time but also complicated handling for the separation of the resulting cedrenone due to many by-products. Especially, a method for producing sec-cedrenol, which is an intermediate product of the process for producing cedrenone, in a large scale has not been established and thus these processes are not satisfactory from an industrial viewpoint.
That is, sec-cedrenol represented by the following formula (II): ##STR3## is a sesquiterpene alcohol which does not exist in nature and only one method has been known for providing sec-cedrenol, which method comprises chemically converting .alpha.-cedrene, which exists in a cedar wood oil, in the presence of a resin acid as disclosed in Blumann et al., Ber. vol. 62, p. 1698 (1929) which is an oxidation catalyst, as disclosed, for example, in Kato, Perfume, No. 123, p. 31 (1978).
This process, however, is not industrially useful because of disadvantages in that it requires not only a prolonged period of reaction time but also complicated handling for the separation of the resulting sec-cedrenol due to many by-products.
Recently, it has been reported that sec-cedrenol and cedrenone have a vasodilation function as disclosed, for example, in Japanese Patent Application No. Hei-3-145236, and studies on the application of these compounds have been started. However, an industrially advantageous process for producing sec-cedrenol and cedrenone must be developed to use sec-cedrenol and cedrenone in various applications.